Age-related functional ability is a dynamic state known to change over time. While there is some knowledge about the events and conditions predictive of functional decline, there is a gap in our understanding of individual trajectories or rates of change of functional ability over time. The goal of this project is to examine antecedent predictors and mediating processes of individual trajectories of change in functional ability across diverse populations. To address error bias, state-of-the-art statistical methodologies will be utilized including latent growth curve, measurement models and missing data strategies. Utilization of these methods will provide unbiased estimates of the rates of change (e.g. the pace and velocity) in functional ability over time. The long-term goals of this project will assess how change in age-related functional ability differs across various ethnic groups and social strata. This work will uncover the biobehavioral mediating mechanisms responsible for function decline. The results will ultimately provide a basis for informing intervention efforts aimed at preventing disabilities. While the candidate possesses the appropriate methodological skills necessary to pursue the proposed research agenda, there is a considerable gap in biomedical experience and theoretical knowledge in geriatrics and gerontology. The major career development objectives of this proposal will provide a solid background in aging studies. This will be accomplished two ways; 1) through formal didactic course work in gerontology, and 2)immersion in mentored research projects addressing change in functional ability. The training will provide the candidate with the necessary medical, biological, and sociological training in aging research that will lead to innovative research as an independent researcher in the area of functional ability. The University of Texas Health Science Center San Antonio (UTHSCSA) has developed nationally recognized education and training programs in aging and geriatrics. Here, the training will be obtained through a series of formal gerontology courses, seminars, workshops, and frequent contact with widely experienced mentors where a series of research projects are proposed.